Fasteners such as nails and staples are commonly used in projects ranging from crafts to building construction. While manually driving such fasteners into a work piece is effective, a user may quickly become fatigued when involved in projects requiring a large number of fasteners and/or large fasteners to be driven into a work piece. Moreover, proper driving of larger fasteners into a work piece frequently requires more than a single impact from a manual tool.
In response to the shortcomings of manual driving tools, power-assisted devices for driving fasteners into work pieces have been developed. Contractors and homeowners commonly use such devices for driving fasteners ranging from brad nails used in small projects to common nails which are used in framing and other construction projects. Compressed air has been traditionally used to provide power for the power-assisted (pneumatic) devices. However, other power sources have also been used, such as DC motors.
Various safety features have been incorporated into pneumatic and other power nailers. One such device is commonly referred to as a work contact element (WCE). A WCE is incorporated into nail gun designs to prevent unintentional firing of the nail gun. A WCE is typically a spring loaded mechanism which extends forwardly of the portion of the nail gun from which a nail is driven. In operation, the WCE is pressed against a work piece into which a nail is to be driven. As the WCE is pressed against the work piece, the WCE compresses the spring and generates an axial movement which is transmitted to a trigger assembly. The axial movement is used to reconfigure a safety device, also referred to as a trigger disabling mechanism, so as to enable initiation of a firing sequence with the trigger of the nail gun.
While the use of a WCE is very effective in preventing inadvertent firing of a nail gun, the location of the WCE can be problematic. Specifically, the WCE blocks the view that an operator has of the location on the work piece into which a nail or other fastener is to be driven. For projects which require fasteners to be driven into precise locations, the visual interference caused by the WCE can result in inaccurate placement of the fastener in the work piece.
Another safety device incorporated into power nailers is the blank fire lockout. The blank fire lockout prevents the nailer from firing when the magazine holding nails or other fasteners is empty or has only a few remaining fasteners. This feature is helpful since firing the device when no fasteners remain in the magazine may reduce the life of the tool and may prevent damage to the work piece which thus user must then repair. In past devices, the blank fire lockout mechanism includes a pivoting arm configured to block the path of the WCE when the magazine reaches a low level. The pivoting arm prevents the WCE from being depressed which, in turn, blocks the trigger from being depressed. Thus, the nailer cannot be fired when the fastener magazine is empty.
In past nailers incorporating blank fire lockout mechanisms, the nose of the nailer must be bulky and large in order to accommodate the interaction between the WCE arrangement and the blank fire lockout mechanism. This further blocks the view of the operator and reduces the maneuverability of the device.
What is needed is a safety system which can be used to prevent inadvertent nail gun firing while providing an operator with an unobstructed view of the location into which a fastener is to be driven. What is further needed is a blank fire lockout system configured for use with the WCE arrangement that allows for a reduced nose size and increases user visibility.